# The magnetic flux linked with a coil (in Wb) is given by the equation ϕ = 5t^2 + 3t + 16 The magnitude of induced emf

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The magnetic flux linked with a coil (in Wb) is given by the equation

$\phi=5t^2+3t+16$

The magnitude of induced emf in the coil at the fourth second will be

(1) 10 V

(2) 33 V

(3) 43 V

(4) 108 V

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Ans: (3) 43 V

Sol. The magnitude of induced emf is given by

$|\varepsilon|={d\phi_B\over dt}={d\over dt}(5t^2+3t+16)$

$|\varepsilon|=10t+3+0$

at t = 4 s

$|\varepsilon|=10\times4+3$

$|\varepsilon|=43V$

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Ans: (3) 43 V

Explanation: